Hello, 

I want to check the file header before ( or after ) I upload an Attachment ( File )
to an Sharepoint Item. 

Is there a way/solution to read the file header ( hex read ) ?

Based on the information I get from the "stream" I want to classify
the file/attachment in sharepoint ( e.g. wrong header / correct header )

Second solution:
I could also upload all files and the run a "check header tool" within Sharepoint.
Is this possible ?

Regards,
Steve

Hi,

You can try to identify the extension of the file through event receiver before and after upload.

Try this, are you looking for this ?

var extension = Path.GetExtension(FileStreamObj.Name);

Hi, thank you, this would get the extension of the file...

But I want to read the header of the (binary) file, 
I need "something" to stream the file, then look for the characters
in the stream...

Based on different headers I want to classify the file ( set a field in sharepoint ),
but this is secondary task.

Is there somehow a function ( with Sharepoint Services or Javascript or C# )
to read the binary header?

Best regards
Steve

Hi,

Are you trying to read the contents  of the file for scanning the specific keyword before upload Or after upload ?

if yes, here is code snippet

string contents;
using(var sr = new StreamReader(fileStream))
{
   contents = sr.ReadToEnd();
}

Now you can check the content string, if your condition met add your logic to add the file to Document Library.